Geography – The Andes Mountains (The Inca)
The Andes are some of the tallest, starkest mountains in the world. The Andes cover a distance of some 5,500 miles (8,900 kilometres)—from the southern tip of South America to the continent’s northernmost coast on the Caribbean. The Andes contain the highest peaks in the Western Hemisphere. The Andes offer several challenges to anyone living there. First, there is a lack of flat land for agriculture. Second, the weather can be very harsh and change without warning. The Andes experience everything from scorching sun to freezing temperatures. Third, it is difficult to travel through the Andes making travel, communication, and trade challenging.
Despite these challenges, the Inca found ways to thrive in the Andes Mountains. One important technological innovation was terrace farming. To create more land for agriculture, they cut terraces into the hillsides, progressively steeper, from the valleys up the slopes. The terraces leveled the planting area, but they also had several unexpected advantages. The stone retaining walls heat up during the day and slowly release that heat to the soil as temperatures plunge at night, keeping sensitive plant roots warm during the sometimes frosty nights and expanding the growing season. And the terraces are extremely efficient at conserving scarce water from rain or irrigation canals. The Incans knew to mix the soil with gravel so that the water could drain out and would not become trapped. Researchers say that the Incan terraces are even today probably the most sophisticated in the world, as they build on knowledge developed over about 11,000 years of farming in the region.
Another important technological innovation was the Incan system of roads. Inca roads covered over 40,000 km (25,000 miles), principally in two main highways running north to south across the Inca Empire, which eventually spread over ancient Peru, Ecuador, Chile, Bolivia, and Argentina. Roads were also built which went beyond Inca-controlled settlements and led to outside territory, perhaps to facilitate trade with, or military operations against, neighboring peoples. Inca engineers were also undaunted by geographical difficulties and built roads across ravines, rivers, deserts, and high-altitude mountain passes.
The extensive reach of the road network allowed the Incas to better move armies across their territories in order to further expand the empire or maintain order within it. Trade goods and tribute from conquered peoples - both goods and people – could also be easily transported to and from the major Inca centers, typically using llama caravans and porters (there were no wheeled vehicles). Inca administrative officials also travelled along the roads in order to dispense justice or maintain records such as local agricultural production, tribute quotas, and censuses. Ordinary people were not permitted to use the roads for private purposes unless they had official permission. They also sometimes had to pay tolls for the privilege, especially at bridges.
Another interesting feature of Inca roads was the use of runners. Moving as fast as they could, they operated in relays, passing information to a fresh runner stationed every six to nine kilometers. However, it was not only messages that were carried between population centers but also such perishable items as fresh fish and seafood for the tables of Inca nobles. With this system, information (and fish) could travel up to 240 km in a single day.